Does anyone know a place to find mechanical drawings, renderings, etc., for various engines, transmissions, and so on? For example, the bell housing pattern for a chevy, olds, ford, crankshaft flywheel bolt patterns, cylinder head bosses, and more.
This pops up every now and then....and then disappears quickly, when it is again discovered that there really isn't any such thing. Here's a thread from 17 years ago, I bet you'll find a lot more in your search.... https://www.jalopyjournal.com/forum/threads/where-to-find-engine-blueprints-dimensions.73172/ Here's a more recent one https://www.jalopyjournal.com/forum/threads/engine-dimension-drawings.1177268/
I have a solid CAD model of a sbc that I got from Mercury marine years ago. It has the Chevy bellhousing pattern as well as other defining features to mount one. However, I haven’t ever found much else.
Thanks guys, that's a good start for sure. Has anyone here ever had an engine or trans 3D laser scanned for dimensional purposes into CAD?
It looks like an amazing technology. I have a buddy who has done it on various projects to replicate parts where there is no aftermarket or replacement option available, but I have never done it and have no idea what the cost is involved in it. I'm sure for certain stuff you can get it pretty close just by taking some crude measurements and calculations. But other stuff, like a bell housing pattern with dowel pins relative to crank centerline, really need to be very accurate.
Yep, it is a cool technology, but also pretty expensive for a scanner to do parts that are very big. I am pretty sure the one we are getting would be big enough to do about anything I might want to scan on a car. We will see...
There are some 3D scans on the 3D model sites, generally not free, and not in freeware-readable file formats. Also, accurate scans tend to make for huge files. Fairly accessible software can reduce the vertex count significantly, but at an equally significant loss of accuracy. Beware of the 3D model sites, though. People will post three boxes with four ¾" tubes on each side and call it a 392 Hemi. Trust nothing.
Just curious, what kinda of part(s) are you looking to make? I can see BH adapters, but was just wondering.
I've seen odd ones too for transmission bolt patterns. Older stuff you can sometimes fake yourself through. With a good straight edge and a precision scale, you can come up with a good part rendering. Just about any spacing will fall into something fractional. Double check yourself by using center lines. Most patterns are symmetrical. If you have CAD access and a decent plotter (B size or larger) do a print out and see how well it matches up to the part in question.
I went back into the HAMB archives and found the thread by DONWOW where he built a removable bell housing adapter to go from Early Olds engine to Chevy trans out of a Hydramatic torus. I want to try my hand at something similar. except use some more common parts to streamline the manufacturing process. I figure there are 2 main precision coordinates; one on the engine (the bell housing pattern), and the bolt pattern/fitment on the front pump of the transmission. If I started with something like a JW Superbell or Quicktime bell housing for the chevy trans, or in the alternative, a 4 speed bell housing for an early Olds, I'm potentially half-way there. The starting point already has one pre-made, accurate set of coordinates, and would then need to be aligned with the other. Similarly, there was a company called Tanson Enterprises in Sacramento, CA that would simply mill off an appropriate amount of the stock Chevy transmission case, and weld on an Early Olds pattern. However, they are long out of this business and do not offer this service any longer. A real shame. I have at least 2 vehicles right now where I want to mate an Early Olds to a GM trans. So I would want to make myself a fixture/jig so that the process and parts are repeatable.
The Jalopy Journal
